U.S. Pat. Nos. 3,505,635, Re. 28,328, and 4,525,016, disclose electrical test probes of the type having a pair of electrical contacts at its forward end, a tubular body member and a movable sleeve located around the tubular body member. The sleeve is movable between rearward and forward positions relative to the tubular body member to cause latch means to be moved to latching and unlatching positions. The purpose of the latch means is to latch the probe inside of a well or opening of an aircraft to test the electrical circuit employed for firing an explosive charge carried by a cartridge.
Some wells or openings now in use which support the cartridges have reduced diameter entrances. This makes the testing more difficult since the test probe must be centered in the opening in order to make proper electrical engagement between the electrical contacts of the probe and of the circuit to be tested.